Topology optimization of anode catalyst layer for polymer electrolyte membrane water electrolyzers considering the effect of gas coverage

Hydrogen is a highly sustainable and clean energy alternative to fossil fuels. However, its major drawback is that hydrogen is predominantly found in nature as part of other molecules, such as water, crude oil, or natural gas, necessitating the production of clean hydrogen, commonly referred to as green hydrogen. Polymer electrolyte membrane water electrolyzers (PEMWEs) show great promise in efficiently producing green hydrogen due to their rapid response to electricity variations. However, the cost of electrode fabrication remains a challenge, mainly due to the high loading of expensive iridium-based catalysts. To address this issue, this study employs topology optimization (TO) to optimize the design of the anode side catalyst layer in PEMWEs by controlling the volume fractions of material constituents. The objective is to achieve an optimal configuration that maximizes performance while considering the effect of gas coverage, generated by reactions on the active surface area. The findings demonstrate a heterogeneously distributed structure through the TO process. While comparing TO results to those of a homogeneous electrode, it is observed that the TO results exhibit lower performance in the low voltage region (1.23-1.83 V). However, in the high voltage region (2.03-3.23 V), the results obtained from TO show a remarkable 3.5 times improvement in performance compared to the homogeneous electrode. This finding is significant because, in the future, researchers will be seeking ways to operate PEMWEs at high current densities in the high voltage region to reduce costs. The optimized structure offers valuable insights for researchers and engineers working on the development of efficient and economically viable PEMWE systems for green hydrogen production, fostering the transition towards a more sustainable energy future.